The Clinical Core operates as the unit of the OADC with responsibility for identification, recruitment, characterization, and follow-up of populations of well-characterized subjects for clinical dementia research. In order to fulfill this mission, the Clinical Core completes systematic assessments resulting in standardized diagnoses of the research cohort which are then entered into the relational database of the OADC. Many types of data are collected in order to be responsive to current and anticipated needs of the research community; clinical histories, physical and neurological examinations, neuropsychological and behavioral assessments, and laboratory data. The Clinical Core works closely with the other Cores of the Center to ensure if possible tissue donations (Neuropathology Core), characterization of genetic-associations (Genetics Core) and smooth transfer, entry, storage and eventual retrieval for analysis of the data. The Clinical Core is dedicated to on-going evaluation of its identified cohorts and to ensuring that no subjects are lost to follow-up. Several groups form a particular focus of the Clinical Core. These include Alzheimer disease patients, Parkinson disease patients and healthy elderly control subjects. The latter subjects are formed primarily from a unique community-based population of oldest old (those 85 years or older) who are at high risk to develop incident dementia over a five year period. The Clinical Core also enhances its research mission of the OADC through its Satellite Programs comprising of two main components: (1) an African-American minorities program in Northeast Portland targeted to enroll at least a representative sample of all elderly African-Americans with dementia in the Portland metropolitan area and (2) a rural Oregon program which enrolls subjects from 3 rural counties and Native Americans over 65 years of age residing on the Warm Springs Reservation. Clinical Core personnel will also function as a resource for consultation and guidance in designing and operating research projects in their early or developmental phases or to problem-solve at latter stages. Members of the Clinical Core will participate frequently in the educational and information transfer activities of the OADC.